Malodors are usually caused by chemicals that are perceived at very low concentrations. Although malodors may not necessarily be dangerous to health at low levels, they can affect one's enjoyment of the environment. Among those malodors, shoe/foot odor is a common problem in people's daily life.
Conventional deodorizers include powders and sprays. Deodorant powders use a variety of ingredients such as inorganic compounds of aluminum, zinc, and zirconium to provide a desired effect. However, powders and sprays can cause a mess and it is almost impossible to apply the powder or spray into some locations, such as the foot portion of high boots or a high top sneakers.
Other conventional deodorizes include shoe insoles or patches.
Usually relatively high loading of fragrance containing perfumes (i.e. about 10 milligrams (mg) or greater) may be used in the compositions of the insoles or spray, to provide sufficient “odor masking” by diffusing fragrance into the environment to mask the malodors. Such concentrated loadings of fragrance in the perfume component can be expensive and cause the adhesive holding the deodorizer to the footwear to soften, causing the deodorizer to loosen from the footwear.